1. Field of the Invention
This invention relates generally to disposable paperboard containers, and more particularly, to such containers having anti-skid protuberant means on the under-surface thereof to prevent a stacked tray of containers from slipping or sliding inadvertently one with respect to another.
2. Description of the Prior Art
Packaged goods such as beverages commonly are contained in cylindrical containers or cans and then arranged in aligned rows on a paperboard tray. In shipment and storage, such trays with the cans arranged thereon usually are stacked in high columns to conserve floor space in the transport vehicle or at the point of sale of the canned product.
The paperboard trays with lading thereon stacked one above another have a tendency to move or slip inadvertently with respect to each other because of the relatively low coefficient of friction between the bottom surface of one tray and the can lips upon which such tray rests. This slipping of loaded trays is of particular concern when the stacked trays with lading are transported in a vehicle; sudden stops, starts or turns of the vehicle may cause its load of trays to shift and fall resulting in possible damage to the containers and the product retained therein.
Various means are known for the provision of anti-skid container trays which avoid the aforesaid problems. For example, U.S. Pat. No. 3,490,583 discloses use of an abrasive material sprayed on the underside of the trays to prevent movement when the same are stacked. U.S. Pat. No. 3,982,654 teaches a plastic case system with the underside surface having recesses to receive the crowns of containers in an adjacent case and lock the same together to prevent movement. Similar arrangements are disclosed in U.S. Pat. Nos. 2,907,509, 3,349,943, 3,391,814 and 3,964,607. None of the aforementioned patents, however, is concerned with the provision of the expedient means of providing anti-slip surfaces for such trays by forming protuberances on the underside thereof for interaction with the tops of the lading in a next-adjacent stacked tray.